Colloid effect on permeability losses of water-bearing media under different sodium absorption ratio

Column experiment was conducted to elucidate the transport-deposition dynamics of colloid in the coastal porous media in Tianjin under different sodium absorption ratio (SAR). the permeability changes of the water-bearing media, and the particle size, zeta (ζ) potential and electrophoretic mobility of the colloid were measured. Results showedthat deposition occurred during the transport of colloid in the water-bearing media, and the total deposition ratio of colloids were 50.96 %, 87.95 % and 54.24 % respectively for the sodium absorption ratio (SAR) of 0, 2.85 and ∞. The average particle size of colloid in effluent decreased with increasing the absorption ratio (SAR), and the average particle size of colloid in effluent were in the range of 166.1~1595.9 nm, 578.6~2082.7 nm and 436.4~751.8 nm respectively for the sodium absorption ratio (SAR) of 0, 2.85 and ∞. Furthermore, Zeta (ζ) potential and electrophoretic mobility of colloid in effluent were negative, and the absolute value of zeta (ζ) potential and electrophoretic mobility increased with increasing the absorption ratio (SAR). When sodium absorption ratio (SAR) of influent were 0, 2.85 and ∞, permeability losses of the water-bearing media were 99.0%, 97.3% and 38.0% respectively in the process of colloids deposition, and it showed that the transport-deposition of colloid had influence on permeability of the water-bearing media, and permeability losses of the water-bearing media decreased with increasing the absorption ratio (SAR).